3D FEM modelling of an electro-optical micro-shutter

In the present paper, we describe the results of the 3D FEM modelling performed by the University of Bordeaux on the micro-shutter devices developed by Centro Ricerche Fiat. After a brief introduction on recent works about shutters in the Fiat Research Center, the authors describe the FEM modelling of a micro-shutter device. The next section presents the numerical methodology used for this electro-mechanical coupled study. The coupled study is made in two steps: first, an electrostatic analysis is computed to determine the force acting on the flexible conductor; then a structural analysis is performed to obtain the deformation which is used to remesh the electrostatic model. The next section shows results of computations and different threshold voltages obtained in functions of the petal and dielectric layer thickness. These results indicate how threshold voltages are very dependant on these geometrical parameters. In conclusion, the authors explain the interest of this numerical tool for the prediction of optimum parameters before designing a micro-shutter device.